1. Technical Field
The present disclosure relates to fenestrations and, in particular, to framing structures used to frame building fenestrations.
2. Description of Related Art
Fenestration frames, such as door frames and window frames used in commercial and residential construction, provide a structural and sometimes decorative interface between the framed opening and the adjacent building wall. Typically, fenestration frames use a combination of wood and/or metal to provide an appropriately sized, framed opening for receipt of a window or door, while also providing a weather resistant seal between the outside surface of the building and the interior wall structures. In one standard arrangement, wooden framing structures are arranged around the periphery of an opening in a wall to form a sill/threshold at a lower edge, a header at an upper edge, and jambs at the side edges. These four framing structures are dimensionally controlled to provide a framed opening sized to receive a particular window or door. Each framing structure may be made from various kinds of material, such as certain species of wood chosen for workability, resistance to damage from weather and impact, and insulative value. Many hard woods and some soft woods are known to be suitable for fenestration framing.
For example, FIG. 1 schematically illustrates a solid-core fenestration framing member 10 having an interior surface 12 adapted to face inwardly toward the interior of a building, and an opposed exterior surface 14 adapted to face outwardly from the exterior of the building. A single monolithic material extends across the frame width W1. In some applications, framing member 10 may be formed from a resilient material such as hardwood, which provides a durable wear surface at interior and exterior surfaces 12, 14. However, such hardwood materials may be costly and may have insufficient resistance to thermal transfer (i.e., its “R-value”) for some applications.
In some cases, moisture barriers are also used at the exterior of the fenestration frame for additional weather resistance. Such moisture barriers are typically made of aluminum or vinyl. Thermal barriers may also be employed, including foam insulation or other insulative materials, to impede heat and/or air exchange between the interior and exterior of the building around gaps between the fenestration frame and the adjacent structures.